Clobetasone Butyrate EP Impurity I CAS 639817-47-3
| CAS No. | 639817-47-3 |
| Molecular Formula | C26H32ClFO5 |
| Molecular Weight | 478.98 g/mol |
| Category | Pharmacopoeial Impurity Standards / EP Impurities |
| Availability | In Stock |
Chemical Structure
Description
The molecular framework of Clobetasone Butyrate EP Impurity I (C26H32ClFO5) is characterized by a steroid core, a hydroxyl group, an ether linkage, fluorine/chlorine substitution. In reversed-phase chromatography, its retention is governed primarily by the polarity and ionization state of its functional groups, which provides a practical basis for HPLC-UV/DAD or LC-MS method development. The presence of an aromatic ring or conjugated system gives the compound characteristic absorption bands in the UV-Vis region, making it well suited to UV or diode-array detection (DAD).
Clobetasone Butyrate EP Impurity I (CAS 639817-47-3) is a certified pharmaceutical impurity reference standard with the molecular formula C26H32ClFO5 and a molecular weight of 478.98 g/mol.
Recommended for quantitative analysis by HPLC, GC, LC-MS/MS, or GC-MS as an external calibration standard; it can also be used for spiked-recovery experiments, LOD/LOQ determination, and LC-MS/MS multiple-reaction-monitoring (MRM) calibration.
As a certified reference material (CRM), Clobetasone Butyrate EP Impurity I meets the metrological traceability requirements of ISO/IEC 17025 laboratories. Batch-to-batch consistency is monitored via control charts to guarantee comparable assigned values across lots.
Physical & Chemical Properties
| Molecular Formula | C26H32ClFO5 |
| Molecular Weight | 478.98 g/mol |
| Appearance | Pale yellow to yellow crystalline powder. (slight halide-like odor, low volatility) |
| Purity | ≥95% |
| Storage | Store at room temperature, protect from light, keep sealed and dry |
| Solubility (reference) | Soluble in methanol, acetonitrile, DMSO, water (slightly soluble) |
| Stability | May oxidize slowly on prolonged air exposure; Light-sensitive; avoid direct strong light; Contains ester bond; hydrolyzes under strong alkaline conditions |
| Degree of Unsaturation (DBE) | 10.0 |
| UV Absorption | UV-absorbing |
| Structural Features | Aromatic ring present |
| CAS Registry Year (est.) | 1985 |
| Halogen Content | F/Cl-containing |
Related Clobetasone Standards
- Clobetasone Butyrate EP Impurity F (CAS 25120-98-3)
- Clobetasone 17-Butyrate (CAS 25122-57-0)
- Clobetasone butyrate EP Impurity E (CAS 639817-48-4)
- Clobetasone butyrate EP Impurity C (CAS 639817-49-5)
- Clobetasone Butyrate EP Impurity H (CAS 25122-56-9)
- Clobetasone butyrate EP Impurity G (CAS CATO-C4X-35394)
- Clobetasone Butyrate Impurity 7 (CAS CATO-C4X-35397)
- Clobetasone Butyrate EP Impurity A (CAS 54063-32-0)
Recommended Standards
- 2-(3-Bromo-4-iodophenoxy)-1,3-difluoro-5-(trifluoromethyl)benzene (CAS 2244087-65-6)
- 2-(3-Bromo-2-iodophenoxy)-1,3-difluoro-5-(trifluoromethyl)benzene (CAS 2244088-68-2)
- 2-(2-Bromo-6-iodophenoxy)-1,3-difluoro-5-(trifluoromethyl)benzene (CAS 2244086-49-3)
- 1-{5-[(4-chlorophenyl)sulfanyl]-4-phenyl-1,3-thiazol-2-yl}-4-(4-fluorophenyl)-1H-pyrazol-5-amine (CAS 956393-87-6)
- Urapidil Impurity 75 (CAS 116315-12-9)
- Obeticholic Acid Impurity 12 (CAS 1885104-64-2)
- Paracetamol EP Impurity M (CAS 1752-24-5)
- Cefprozil Impurity 52 (CAS CATO-C4X-149252)
- 3-(4-Fluoro-6-methylpyridin-2-yl)propan-1-amine (CAS 1393552-73-2)
- 4-Chloroaniline-2,3,5,6-d4 (CAS 191656-33-4)
- 3-Amino-N-(4-bromo-2-fluorophenyl)-6-(pyridin-4-yl)thieno[2,3-b]pyridine-2-carboxamide (CAS 625370-65-2)
- 4-Phenyl-1H-benzo[d][1,3]oxazin-2(4H)-one (CAS 13260-76-9)
- 4-(3-Bromo-2-methylpropyl)-1-ethyl-1h-pyrazole (CAS 1341411-49-1)
- [5-31]-Semaglutide (CAS CATO-C4X-2226263)
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